Why does my iPhone 6 die so quickly now?

I dropped my phone and broke it and had to switch to my old iPhone 5c, which had a horrible battery life. I finally got my iPhone 6 fixed, but now my battery dies so much quicker then before. I'm on battery saving mode, I have bluetooth off and my screen brightness is usually down almost all the way. I do listen to music while i'm in school but that has never been a big problem before and all my apps are closed. What's the problem?

****CONTINUED**** Another thing, I have broke this phone before and have had the screen replaced before. And my location's for my apps are mostly turned off. In a matter of typing both of these, I have lost nearly 10% and I do not use a lot of data. It also charges extreamly slow even when on battery saving mode it will go from 100% to 75% in a matter of an hour and a half of not using it at all. Again, this has never been a problem before and it is the exact same phone with the same settings, just a different screen.

  • Why does my iPhone battery die so quickly? I had my iPhone for about a year and a half, and recently I've noticed that the battery is draining incredibly fast. I've always had it on 3g internet/Wi-Fi and the battery never died this fast so I don't know what the exact problem is. I charged it to 100% yesterday and I only used it for maybe about 10 minutes and left it untouched for the rest of the night. Today when I woke up the phone was dead. I haven't changed the settings or anything fyi.
  • Why does my iPhone battery die so fast? I have boost magic, which is supposed to help my battery last longer, and I kill all my apps when I'm done using them. I go from 100 at 8am and I'm at 60 by 9:30am. And I hardly use it too, just to look up information quickly and I just set my phone aside. I let it go down to 20% battery and let it charge over night. It just started doing this recently. I also keep my brightness to pretty much 0 with the auto brightness on. And it still dies fast. What can I do?
  • Why does my iPhone 5s die so quickly? It does within 5 hours. Barely on it I just click the power button to check the time and it constantly decreases. I've watched it go down like a clock. What tf is happening to my phone.
  • Why does my iphone 5 die so quickly? I just got my iphone 5 yesterday and after i fully charged it, it dies within 3 hours. The battery seems to decrease so quickly. Why is this happening?